Application of Dynamic and Static Light Scattering for Size and Shape Characterization of Small Extracellular Nanoparticles in Plasma and Ascites of Ovarian Cancer Patients

In parallel to medical treatment of ovarian cancer, methods for the early detection of cancer tumors are being sought. In this contribution, the use of non-invasive static (SLS) and dynamic light scattering (DLS) for the characterization of extracellular nanoparticles (ENPs) in body fluids of advanced serous ovarian cancer (OC) and benign gynecological pathology (BP) patients is demonstrated and critically evaluated. Samples of plasma and ascites (OC patients) or plasma, peritoneal fluid, and peritoneal washing (BP patients) were analyzed. The hydrodynamic radius (Rh) and the radius of gyration (Rg) of ENPs were calculated from the angular dependency of LS intensity for two ENP subpopulations. Rh and Rg of the predominant ENP population of OC patients were in the range 20–30 nm (diameter 40–60 nm). In thawed samples, larger particles (Rh mostly above 100 nm) were detected as well. The shape parameter ρ of both particle populations was around 1, which is typical for spherical particles with mass concentrated on the rim, as in vesicles. The Rh and Rg of ENPs in BP patients were larger than in OC patients, with ρ ≈ 1.1–2, implying a more elongated/distorted shape. These results show that SLS and DLS are promising methods for the analysis of morphological features of ENPs and have the potential to discriminate between OC and BP patients. However, further development of the methodology is required.

Regularized Stokeslets Lines Suitable for Slender Bodies in Viscous Flow

Slender-body approximations have been successfully used to explain many phenomena in low-Reynolds number fluid mechanics. These approximations typically use a line of singularity solutions to represent flow. These singularities can be difficult to implement numerically because they diverge at their origin. Hence, people have regularized these singularities to overcome this issue. This regularization blurs the force over a small blob and thereby removing divergent behaviour. However, it is unclear how best to regularize the singularities to minimize errors. In this paper, we investigate if a line of regularized Stokeslets can describe the flow around a slender body. This is achieved by comparing the asymptotic behaviour of the flow from the line of regularized Stokeslets with the results from slender-body theory. We find that the flow far from the body can be captured if the regularization parameter is proportional to the radius of the slender body. This is consistent with what is assumed in numerical simulations and provides a choice for the proportionality constant. However, more stringent requirements must be placed on the regularization blob to capture the near field flow outside a slender body. This inability to replicate the local behaviour indicates that many regularizations cannot satisfy the no-slip boundary conditions on the body’s surface to leading order, with one of the most commonly used blobs showing an angular dependency of velocity along any cross section. This problem can be overcome with compactly supported blobs, and we construct one such example blob, which can be effectively used to simulate the flow around a slender body.

Modeling and Simulation of Five-Phase Synchronous Reluctance Motor Fed By Five-Phase Inverter

Five-phase machine employment in electric drive system is expanding rapidly in many applications due to several advantages that they present when compared with their three-phase complements. Synchronous reluctance machines(SynRM) are considered as a proposed alternative to permanent magnet machine in the automotive industry because the volatilities in the permanent magnet price, and a proposed alternative for induction motor because they have no field excitation windings in the rotor, SyRM rely on high reluctance torque thus no needing for magnetic material in the structure of rotor. This paper presents dynamic simulation of five phase synchronous reluctance motor fed by five phase voltage source inverter based on mathematical modeling. Sinusoidal pulse width modulation (SPWM) technique is used to generate the pulses for inverter. The theory of reference frame has been used to transform five-phase SynRM voltage equations for simplicity and in order to eliminate the angular dependency of the inductances. The torque in terms of phase currents is then attained using the known magnetic co-energy method, then the results obtained are typical.

Hypothesis on the Influence of the Magnetic Behaviour of Hydrogen Doped Zinc Oxide during Its Plasma Sputtering Process

We investigate the complexity of the reactive sputtering of highly conductive zinc oxide thin films in the presence of hydrogen at room temperature. We report on the importance of precise geometric positioning of the substrate with respect to the magnetron to achieve maximum conductivity. We examine the electrical properties of the deposited thins films based on their position on the substrate holder relative to the magnetron. By considering early reports by other researchers on the angular dependency of plasma parameters and the effect of hydrogen doping on electric and magnetic properties of hydrogen-doped zinc oxide, we propose a hypothesis on the possibility of such properties resulting in the observations presented in this report pending further tests to verify this hypothesis. Overall, in this report we present the guide by which highly conductive zinc oxide thin film coatings can be prepared via RF sputtering with hydrogen presence along with argon as the sputtering gas.

A Hybrid Ray-Tracing Optical Model for Compound Parabolic Concentrators

Compound parabolic concentrator (CPC), as a hybrid of the stationary and the tracking collectors, can collect both direct beam and diffuse radiation. CPCs are favorable choices for medium-temperature applications for their high thermal efficiency and their cost-effectiveness. Optical models are important tools to predict the solar concentrating capability of the CPC. Despite the numerous, optical models developed in the literature and used for parametric studies of the optical characteristics of CPCs, the angular optical properties of the glass envelope, reflector, and receiver are rarely included. Moreover, most existing optical modeling studies of CPCs did not consider or present the loss associated with the refraction in the glass envelope. This study aims to fill these gaps by developing a comprehensive CPC optical model with the capability of profile generation, hybrid ray-tracing (HRT), surface property simulation, and sky model. The HRT can achieve high accuracy using significantly fewer computation resources compared with Monte Carlo ray-tracing (MCRT) and was validated against tracepro. The new optical model incorporates angular and spectrum dependence of optical properties for refraction and reflection using multilayer thin-film theory. Finally, the proposed HRT model was used to analyze the error associated with neglecting geometric design parameters and angular dependency of optical properties in optical simulation. The results suggest that the gaps between the receiver, glass envelope, and the reflector, the refraction of the glass and angular dependence of transmittance, and absorptance should be included in simulation to avoid considerable errors.

Opal-Like Photonic Structuring of Perovskite Solar Cells Using a Genetic Algorithm Approach

Light management is an important area of photovoltaic research, but little is known about it in perovskite solar cells. The present work numerically studies the positive effect of structuring the photo-active layer of perovskite material. This structuration consists of a hybrid absorbing layer made of an uniform part and an opal-like part. A genetic algorithm approach allows us to determine the optimal combination among more than 1.4 × 10 9 potential combinations. The optimal combination provides an internal quantum efficiency of 98.1%, nearly 2% higher than for an equivalent unstructured photo-active layer. The robustness of the optimum against potential experimental deviations, as well as the angular dependency of the proposed structure, are examined in the present study.

On Microwave Imaging with Absorbing Metasurface Enclosure

Matching fluids used in microwave imaging are often lossy to reduce the reflections from the system enclosure. To enable the use of low-loss matching fluids, we investigate the use of absorbing metasurfaces as the enclosure. This has the potential to enhance the signal-to-noise ratio of the data, thus, enhancing the achievable image accuracy. The presented example has the following limitation: as opposed to design and simulation of the physical structure of the metasurface enclosure, it uses two impedance boundary conditions on top of a metallic-backed substrate. Thus, the angular dependency of a practical absorber is not completely taken into account by this model. At the conference, we'll also consider a microwave imaging metasurface enclosure via design and simulation of a physical structure.

On Microwave Imaging with Absorbing Metasurface Enclosure

Matching fluids used in microwave imaging are often lossy to reduce the reflections from the system enclosure. To enable the use of low-loss matching fluids, we investigate the use of absorbing metasurfaces as the enclosure. This has the potential to enhance the signal-to-noise ratio of the data, thus, enhancing the achievable image accuracy. The presented example has the following limitation: as opposed to design and simulation of the physical structure of the metasurface enclosure, it uses two impedance boundary conditions on top of a metallic-backed substrate. Thus, the angular dependency of a practical absorber is not completely taken into account by this model. At the conference, we'll also consider a microwave imaging metasurface enclosure via design and simulation of a physical structure.